Python importing a module from a parallel directory

Question

How would I organize my python imports so that I can have a directory like this.

project |      \ |      __init__.py |      src |   \ |    __init__.py |    classes.py | test     \      __init__.py      tests.py 

And then inside /project/test/tests.py be able to import classes.py

I've got code looking like this in tests.py

from .. src.classes import(     scheduler     db ) 

And am getting errors of

SystemError: Parent module '' not loaded, cannot perform relative import 

Anyone know what to do?

Answer 1

Python adds the folder containing the script you launch to the PYTHONPATH, so if you run

python test/tests.py 

Only the folder test is added to the path (not the base dir that you're executing the command in).

Instead run your tests like so:

python -m test.tests 

This will add the base dir to the python path, and then classes will be accessible via a non-relative import:

from src.classes import etc 

If you really want to use the relative import style, then your 3 dirs need to be added to a package directory

package * __init__.py * project * src * test 

And you execute it from above the package dir with

python -m package.test.tests 

See also:

• https://docs.python.org/2/using/cmdline.html
• http://www.stereoplex.com/blog/understanding-imports-and-pythonpath